Plant box



FIG. 1 is a top plan view of a plant box, showing my new design;

FIG. 2 is a front elevational view thereof;

FIG. 3 is a right side-elevational view thereof;

FIG. 4 is a left side-elevational view thereof;

FIG. 5 is a rear elevational view thereof; and,

FIG. 6 is a bottom plan view thereof. 

The ornamental design for a plant box, as shown and described. 